Cylindrical sleeve support structure for adjustment of web contacting surface of pick-up bar in a papermaking machine

ABSTRACT

A pick-up bar is used in line between a Fourdrinier machine and a Yankee dryer to help transfer the wet fibrous sheet on the screen conveyor of the Fourdrinier machine to the rotary drum on the dryer. It consists of a rotary shaft supported in a cradle consisting of a sleeve slightly larger in diameter than the shaft, which is slit along its entire length to expose a lengthwise segment of the shaft. The sleeve is supported along its length by a rigid tubular base and the shaft is rotatively fixed within the sleeve by end clamps secured to the tubular base. When the exposed shaft segment surface becomes worn, the end clamps are loosened and the shaft is turned to expose a fresh surface of the web. Several such fresh surfaces can be framed in the slit by turning the shaft in this fashion, and after the entire surface of the shaft has been used, the shaft can be slid out of its sleeve for machining or replacement by another shaft.

United States Patent [1 1 Cloutier [451 Feb. 25, 1975 CYLINDRICAL SLEEVE SUPPORT STRUCTURE FOR ADJUSTMENT OF WEB CONTACTING SURFACE OF PICK-UP BAR IN A PAPERMAKING MACHINE [76] Inventor: Joseph V. Cloutier, 110 Park St.,

Berlin, NH. 03570 [22] Filed: Oct. 25, 1973 [2l] Appl. No.: 409,685

Primary ExaminerS. Leon Bashore .Assistant Examiner-Richard H. Tushin Attorney, Agent, or FirmCesari and McKenna [57] ABSTRACT A pick-up bar is used in line between a Fourdrinier machine and a Yankee dryer to help transfer the wet fibrous sheet on the screen conveyor of the Fourdrinier machine to the rotary drum on the dryer. lt consists of a rotary shaft supported in a cradle consisting of a sleeve slightly larger in diameter than the shaft, which is slit along its entire length to expose a lengthwise segment of the shaft. The sleeve is supported along its length by a rigid tubular base and the shaft is rotatively fixed within the sleeve by end clamps secured to the tubular base. When the exposed shaft segment surface becomes worn, the end clamps are loosened and the shaft is turned to expose a fresh surface of the web. Several such fresh surfaces can be framed in the slit by turning the shaft in this fashion, and after the entire surface of the shaft has been used, the shaft can be slid out of its sleeve for machining or replacement by another shaft.

7 Claims, 3 Drawing Figures CYLINDRICAL SLEEVE SUPPORT STRUCTURE FOR ADJUSTMENT OF WEB CONTACTING SURFACE OF PICK-UP BAR IN A PAPERMAKING MACHINE BACKGROUND OF THE INVENTION This invention relates to apparatus for handling the .wet fibrous sheet during certain paper making pro- .cesses. It relates more particularly to an improved pick- Fourdrinier machine to the felt drum on the dryer. In

use, the drum is arranged to kiss the surface of the pickup bar so that the fibrous web is advanced into the nip between the drum and the bar with the result that the felt on the drum picks up the web from the bar and draws it into the dryer.

Conventionally, the pick-up bar takes the form of a solid cylindrical stainless steel shaft which is oriented at right angles to the direction of web travel, and which is at least as long as the width of the web.

In the paper making process, it is essential that the pressure at the nip between the pick-up bar and the felt drum be uniform across the entire width of the web.

- Otherwise, the web may not be transferred properly to the dryer with resultant damage to the web. This means that the surface of the shaft must be machined to be extremely smooth and even. Also, the relatively heavy shaft'must be supported firmly along its entire length, so that it does not sag away from the drum.

lnvariably, in present day machines, the stainless steel shaft is welded to a large diameter coextensive tubular structure which gives the shaft the required support with a minimum amount of weight. Still, however, the support is quite large and massive.

After the pick-up bar has been in use for a time, the exposed surface of the shaft becomes worn, grooved, or scored as a result of the incessant movement of the web over the shaft, as the web is picked up by the tensioned felt surface of the drum. In time, the shaft becomes so worn that it no longer properly performs its function. At this point, the pick-up bar has to be removed from the process line and the shaft machined to restore its smooth surface. This involves removing the shaft and its massive support assembly from the paper making line, and sending the entire assembly out to a machine shopusually off the premices. In the meantime, the line remains shut down or a spare pick-up bar has to be installed in place of the one being repaired. In either event, substantial amounts of down time and labor are involved which increase overall manufacturing costs.

SUMMARY OF THE INVENTION The present invention aims to provide a pick-up bar which can be used for a long period of time before requiring repair.

Another object of the invention is to provide an improved pick-up bar which can be repaired when necessary in a relatively short time.

A further object of the invention is to provide an improved pick-up bar which should present a smooth even surface to the advancing paper web for a longer time than conventional equipment of this type.

Yet, another object of the invention is to provide a pick-up bar which can be repaired or replaced with a minimum amount of labor and equipment.

Other objects will, in part, be obvious, and will, in part, appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

Briefly, the subject pick-up bar consists of a solid, cylindrical, stainless steel shaft. The shaft is supported in a coextensive cradle, consisting of a sleeve which is slightly larger in inside diameter than the shaft diameter. The sleeve is slit along its entire length to expose a lengthwise segment of the shaft. Also, the surfaces of the sleeve on each side of the slit are tapered so that when the shaft is slid endwise into the sleeve, the shaft segment is exposed between the knife edges of the slit.

The sleeve is supported along its entire length with its slit facing upwards by a relatively large diameter rigid tubular base. The shaft is clamped into position within the sleeve by means of end clamps secured to the base.

The exposed segment of the shaft provides the surface which is presented to the advancing web. When this.segment surface becomes worn, the end clamps may be loosened, and the shaft turned by a suitable wrench engaging it at one end. Several new shaft surfaces can be exposed by turning the shaft to align a different shaft segment with the slit in the sleeve. After the entire surface of the shaft has been used, the end clamps can be loosened and the shaft can be slid out of the sleeve and be machined or replaced by another shaft.

This present pick-up bar can last as much as six times longer than a conventional one before it has to be machined. Furthermore, when it becomes necessary to repair the pick-up bar, only the shaft portion has to be removed and sent out for treatment. The rather massive supportstructure can remain in place, and be outfitted with a replacement shaft if desired.

As a result of the foregoing, the down time of the paper making line due to necessary repairs on the pickup bar is kept to a minimum. In addition, when repairs do become necessary one or two men can remove the shaft from its support and using a simple chain fall or the like, they can place it on a truck for transport to a suitable repair facility and install a replacement shaft in the support assembly. Consequently, the present construction results in a considerable financial savings to the paper manufacturer whose paper making process involve the use of a pickup bar.

BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of the nature ,and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing in which:

FIG. 1 is an isometric view illustrating a pick-up bar made in accordance with the present invention shown in association with the felt drum of a Yankee dryer;

FIG. 2 is a view in front elevation of the pick-up bar in FIG. 1, and

FIG. 3 is a view along line 3-3 of FIG. 2.

I DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to FIG. 1 of the drawing, the subject pick-up bar shown-generally at 10, is adjacent to the felt drum 12 of a conventional Yankee dryer. The felt surface 12a of the drum is shown just kissing the top of the pick-up bar, and wet fibrous web W is advanced into the nip between the two.

As seen in FIGS. land 2, the pickup bar consists of a solid, stainless steel, cylindrical shaft 14 whose ends are milled to form square bosses 16, suitable for use as wrench fittings for reasons to be described later. Shaft 14 is carefully machined to provide a very smooth, even surface for presentment to the web as is the custom with this type of equipment. Typically, shaft 14 might be 2 inches in diameter and on the order of 16 feet long.

Shaft 14 is supported along its entire length by a cradle shown generally at 18. This cradle consists of a tubular cylindrical sleeve 22 also made of stainless steel. The inside diameter of sleeve 22 is the same or slightly larger than the diameter of shaft 14, its length being somewhat less. than that of the shaft.

Sleeve 22, or, more particularly, the top of sleeve 22 is slit along its entire length at 24 to expose a lengthwise segment 14a of shaft 14. This segment provides the surface that is presented to the advancing web W. The outside wall portions of sleeve 22 adjacent slit 24 are tapered at 22a so that they feather into the exposed shaft segment 14a, as best seen in FIG. 3. Thus, no part of the sleeve projects up into the path of the advancing web W. For example, with a two inch diameter shaft 14, the slit 24 could. be on the order of one-quarter inch wide to expose enough of shaft 14 to support the advancing web W.

The sleeve 22 is, in turn, supported by a base in the form of a flat steel bar 26. Bar 26 is of substantially the same length as shaft 14, and it is secured to the underside of sleeve 22 at spaced-apart loctions by welds 32 or other suitable means.

Referring, now, to FIGS. 2 and 3, cradle 18 is supported by a large diameter steel pipe 34, the underside of bar 26 being curved to conform the curvature of the pipe. Securement between these two elements is affected by welding or bolting the bar 26 to the pipe 34. Pipe 34 is slightly longer than shaft 14 and it is supported horizontally by relatively massive standards 38 welded or otherwise secured to the opposite ends of the pipe. v

Shaft 14 is drawn endwise into sleeve 22 by a leader (not shown) which includes a segment which is slightly larger in diameter than the inside diameter of the sleeve, inthis case, two inches. As the leader is drawn into the sleeve, the enlarged portion thereof spreads apart or expands the sleeve sufficiently to allow shaft I 14 to enter the sleeve. Desirably also the surface of shaft 14 is coated with a suitable lubricant such as silicone oil to facilitate its entry into the sleeve. As the leader is drawn through successive lengthwise segments of the sleeve, it expands the sleeve sufficiently to permit passage of the shaft 14 into that segment until the entire shaft is properly seated in the sleeve as shown in FIG. 3.

C-shaped clamps 42 are welded or otherwise secured ends of shaft 14 and the ends of the clamps can be drawn together by means of machine screws 44 passing through the upper ends of the clamp and threaded into the lower ends thereof. When the screws 44 are tightened down, the shaft 14 is prevented from moving axially or rotating relative to sleeve 22.

As best seen in FIG. 3, when the exposed surface 14a of shaft 14 becomes worn, a fresh shaft surface can be presented to the incoming web W. This is accomplished simply by loosening clamp screws 44 and engaging a boss 16 on one end of shaft 14 with a suitable wrench (not shown) and rotating the shaft within the sleeve to frame a new segment in slit 24. Following this, the clamp screws 44 are retightened to lock the shaft in place. Following this procedure, with the illustrated shaft and sleeve dimensions, as many as six new shaft surfaces can be presented to the web as illustrated in FIG. 3. Thus, the present pick-up bar 10 should last up to six times longer than a conventional pick-up bar given the same amount of use.

After the entire surface of shaft 14 has been used, the clamps 42 are loosened and the shaft 14 is pulled endwise from the sleeve using the same type of leader described above, and is sent out to a machine shop to restore its surface. In the meantime, a spare shaft 14 can be inserted into the cradle 18 and paper production resumed with a minimum down time.

Since only the shaft 14 has to be removed and transported, the repair or replacement operation can be accomplished in a minimum amount of time by one or two people. This savings in labor and down time is reflected in a corresponding decrease in the overall cost of manufacturing paper, using this type of process.

It should be apparent then, that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative, and not a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described.

What is claimed is:

1. An improved pick-up bar for use in a paper making machine comprising a cylindrical shaft, a cylindrical sleeve snugly engaging around the shaft along its entire length, said sleeve being slit along its length to expose a length-wise segment of the shaft surface, means for supporting the sleeve along its entire length so that the shaft is disposed horizontally and means for preventing rotational and axial movements of, the shaft relative to the sleeve.

2. The pick-up bar defined in claim 1 and further including means on at least one end of the shaft for engagement by a wrench to turn the shaft relative to the sleeve to expose a different shaft surface segment in the sleeve slit.

3. The pick-up bar defined in claim 1 wherein the sleeve wall on each side of the slit is tapered so that the slit sides feather into the exposed segment of the shaft.

4. The pick-up bar defined in claim 1 wherein the supporting means comprise a rigid large diameter pipe extending the length of the sleeve, and means for securing the sleeve to the pipe at points along its length so that the exposed shaft segment faces upwardly.

5. The pick-up bar defined in claim 4 wherein the securing means comprise a rigid bar secured to the outside wall of the pipe along its length, and means for securing the bar to the sleeve at points along its length.

6. The pick-up bar defined in claim 5 further including at least one clamp removably engaged around an end of the shaft and means for securing the clamp to the bar, said clamp being adjustable between a first position wherein the shaft can be rotated in the sleeve and a second position wherein the shaft is fixed with respect to the sleeve.

7. A pick-up bar as defined in claim 1 wherein the shaft is slightly longer than the sleeve so that the shaft ends project from the ends of the sleeve, a boss formed on at least one end of the shaft for engagement by a wrench to turn the shaft within the sleeve to expose a new surface of the shaft in the sleeve slit, and wherein the outside surface portions of the sleeve adjacent the slit are tapered so that the slit edges feather into the exposed segment of the shaft, and wherein the supporting means comprise a rigid rectangular bar secured to the outside wall of the sleeve at points along its entire length, the bar extending beyond the ends of the sleeve, a long rigid pipe secured to the underside of the bar at points along its entire length, and means for stably supporting the tube so that the exposed segment of the shaft is disposed horizontally and faces upwardly. 

1. An improved pick-up bar for use in a paper making machine comprising a cylindrical shaft, a cylindrical sleeve snugly engaging around the shaft along its entire length, said sleeve being slit along its length to expose a length-wise segment of the shaft surface, means for supporting the sleeve along its entire length so that the shaft is disposed horizontally and means for preventing rotational and axial movements of the shaft relative to the sleeve.
 2. The pick-up bar defined in claim 1 and further including means on at least one end of the shaft for engagement by a wrench to turn the shaft relative to the sleeve to expose a different shaft surface segment in the sleeve slit.
 3. The pick-up bar defined in claim 1 wherein the sleeve wall on each side of the slit is tapered so that the slit sides feather into the exposed segment of the shaft.
 4. The pick-up bar defined in claim 1 wherein the supporting means comprise a rigid large diameter pipe extending the length of the sleeve, and means for securing the sleeve to the pipe at points along its length so that the exposed shaft segment faces upwardly.
 5. The pick-up bar defined in claim 4 wherein the securing means comprise a rigid bar secured to the outside wall of the pipe along its length, and means for securing the bar to the sleeve at points along its length.
 6. The pick-up bar defined in claim 5 further including at least one clamp removably engaged around an end of the shaft and means for securing the clamp to the bar, said clamp being adjustable between a first position wherein the shaft can be rotated in the sleeve and a second position wherein the shaft is fixed with respect to the sleeve.
 7. A pick-up bar as defined in claim 1 wherein the shaft is slightly longer than the sleeve so that the shaft ends project from the ends of the sleeve, a boss formed on at least one end of the shaft for engagement by a wrench to turn the shaft within the sleeve to expose a new surface of the shaft in the sleeve slit, and wherein the outside surface portions of the sleeve adjacent the slit are tapered so that the slit edges feather into the exposed segment of the shaft, and wherein the supporting means comprise a rigid rectangular bar secured to the outside wall of the sleeve at points along its entire length, the bar extending beyond the ends of the sleeve, a long rigid pipe secured to the underside of the bar at points along its entire length, and means for stably supporting the tube so that thE exposed segment of the shaft is disposed horizontally and faces upwardly. 